Subject: [PATCH v3 00/12] Initial multi-platform support

From: [email-masked] (Rob Herring)
Date: Fri, 14 Sep 2012 08:00:30 -0500

On 09/13/2012 07:58 PM, Shawn Guo wrote:
> On Mon, Sep 10, 2012 at 08:07:11PM +0100, Jamie Iles wrote:
>> 8<---
>>
>> Subject: [PATCH] ARM: picoxcell: fixup multiplatform breakage.
>>
>> The debug macros had a dependency on mach headers.  Break that
>> dependency and restore building.
>>
>> Signed-off-by: Jamie Iles <[email-masked]>
>> ---
>>  arch/arm/include/debug/picoxcell.S      |    4 ++--
>>  arch/arm/mach-picoxcell/common.c        |   11 ++++++-----
>>  arch/arm/mach-picoxcell/picoxcell_soc.h |   25 -------------------------
>>  3 files changed, 8 insertions(+), 32 deletions(-)
>>  delete mode 100644 arch/arm/mach-picoxcell/picoxcell_soc.h
>>
>> diff --git a/arch/arm/include/debug/picoxcell.S b/arch/arm/include/debug/picoxcell.S
>> index 58d4ee3..7419deb 100644
>> --- a/arch/arm/include/debug/picoxcell.S
>> +++ b/arch/arm/include/debug/picoxcell.S
>> @@ -9,10 +9,10 @@
>>   * accesses to the 8250.
>>   */
>>  #include <linux/serial_reg.h>
>> -#include <mach/hardware.h>
>> -#include <mach/map.h>
>>  
>>  #define UART_SHIFT 2
>> +#define PICOXCELL_UART1_BASE		0x80230000
>> +#define PHYS_TO_IO(x)			(((x) & 0x00ffffff) | 0xfe000000)
> 
> ...
> 
>>  
>>  		.macro	addruart, rp, rv, tmp
>>  		ldr	\rv, =PHYS_TO_IO(PICOXCELL_UART1_BASE)
>> diff --git a/arch/arm/mach-picoxcell/common.c b/arch/arm/mach-picoxcell/common.c
>> index a8b70b5..f6c0849 100644
>> --- a/arch/arm/mach-picoxcell/common.c
>> +++ b/arch/arm/mach-picoxcell/common.c
>> @@ -20,14 +20,15 @@
>>  #include <asm/hardware/vic.h>
>>  #include <asm/mach/map.h>
>>  
>> -#include "picoxcell_soc.h"
>>  #include "common.h"
>>  
>> -#define PHYS_TO_IO(x)		(((x) & 0x00ffffff) | 0xfe000000)
>> +#define PHYS_TO_IO(x)			(((x) & 0x00ffffff) | 0xfe000000)
> 
> So you end up with defining the same thing at two places.  You need to
> somehow ensure any update to PHYS_TO_IO needs to get applied on both
> to keep them synchronized.  This is difficult for maintaining.
> 
> We're running into the exactly same problem when moving debug-macro.S
> for imx.  I believe this is a common issue which needs a common
> solution.
> 
> I would propose to have the static mapping below (imx example) defined
> in something like arch/arm/include/asm/mach/map_imx.h, so that both
> imx machine code and ll-debug code can include it.
> 
> #define IMX_IO_P2V(x)   (                                               \
>                         (((x) & 0x80000000) >> 7) |                     \
>                         (0xf4000000 +                                   \
>                         (((x) & 0x50000000) >> 6) +                     \
>                         (((x) & 0x0b000000) >> 4) +                     \
>                         (((x) & 0x000fffff))))
> 
> Thoughts?

My thought is to use a fixed virtual address across platforms and make
the physical address a config option. Possibly the uart type can also be
a config option. The 8250 one also needs register stride. See here:

http://lists.infradead.org/pipermail/linux-arm-kernel/2012-August/116982.html

Rob

> Regards,
> Shawn
> 
>> +#define PICOXCELL_PERIPH_BASE		0x80000000
>> +#define PICOXCELL_PERIPH_LENGTH		SZ_4M
>>  
>> -#define WDT_CTRL_REG_EN_MASK	(1 << 0)
>> -#define WDT_CTRL_REG_OFFS	(0x00)
>> -#define WDT_TIMEOUT_REG_OFFS	(0x04)
>> +#define WDT_CTRL_REG_EN_MASK		(1 << 0)
>> +#define WDT_CTRL_REG_OFFS		(0x00)
>> +#define WDT_TIMEOUT_REG_OFFS		(0x04)
>>  static void __iomem *wdt_regs;
>>  
>>  /*
>> diff --git a/arch/arm/mach-picoxcell/picoxcell_soc.h b/arch/arm/mach-picoxcell/picoxcell_soc.h
>> deleted file mode 100644
>> index 5566fc8..0000000
>> --- a/arch/arm/mach-picoxcell/picoxcell_soc.h
>> +++ /dev/null
>> @@ -1,25 +0,0 @@
>> -/*
>> - * Copyright (c) 2011 Picochip Ltd., Jamie Iles
>> - *
>> - * This file contains the hardware definitions of the picoXcell SoC devices.
>> - *
>> - * This program is free software; you can redistribute it and/or modify
>> - * it under the terms of the GNU General Public License as published by
>> - * the Free Software Foundation; either version 2 of the License, or
>> - * (at your option) any later version.
>> - *
>> - * This program is distributed in the hope that it will be useful,
>> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> - * GNU General Public License for more details.
>> - */
>> -#ifndef __PICOXCELL_SOC_H__
>> -#define __PICOXCELL_SOC_H__
>> -
>> -#define PICOXCELL_UART1_BASE		0x80230000
>> -#define PICOXCELL_PERIPH_BASE		0x80000000
>> -#define PICOXCELL_PERIPH_LENGTH		SZ_4M
>> -#define PICOXCELL_VIC0_BASE		0x80060000
>> -#define PICOXCELL_VIC1_BASE		0x80064000
>> -
>> -#endif /* __PICOXCELL_SOC_H__ */
>> -- 
>> 1.7.9.5
>>